Backpack



FIG. 1 is a front elevational view of a backpack showing our new design;

FIG. 2 is one side elevational view thereof;

FIG. 3 is another side elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a perspective view thereof.

The broken lines showing a handle, bottom ridges, shoulder straps and fastener pulls illustrate the portions of the design that form no part of the claim. The broken lines on either side of the slide fastener teeth represent stitching.

The crisscross pattern of lines in the drawings represent material and is understood to be distributed uniformly over the surface of the backpack 

The ornamental design for a backpack, as shown and described. 